(USA TODAY) -- A Florida man is presumed dead Friday after the bedroom in which hewas sleeping suddenly collapsed into a 30-foot wide sinkhole thatswallowed up the entire room, including furniture, local officials said.

Attemptsto rescue 36-year-old Jeffrey Bush were in limbo because the ground wastoo unstable for heavy equipment and the hole is expected to expand.

"This is no ordinary sinkhole," Hillsborough County Administrator Mike Merrill said Friday evening. "This is a chasm."

Bush screamed for help when the house in Seffner, Fla., near Tampa, began to collapse around 11 p.m. Thursday.

Hisbrother, Jeremy, rushed into the room and tried to locate his brotherbut had to be rescued himself by a Hillsborough deputy summoned by 911.

"It swallowed his whole bedroom, his dresser -- everything in his room is gone," a distraught Jeremy said.

"AllI could see was the tops of his bed," he said. "So I jumped in the holeand tried digging him out. I thought I could hear him screaming for meand hollering for me, but they couldn't do nothing."

Deputy Douglas Duvall said "the sinkhole was taking the wholebedroom" when he arrived and saw Jeffrey down in the hole struggling tofind his brother.

"I reached him and actually got him by his hand and pulled him out of the hole," Duvall told WTSP. "The hole was collapsing."

Rescue teams, unable to stay inside the unstable structure, lowered amicrophone and video equipment into the hole but have not heard fromthe victim.

Houses on both sides of the damaged structure have also been evacuated.

Damicosaid that at the surface the sinkhole is about 30 feet across, butofficials say the sinkhole spreads to about 100 feet across below thesurface.

An engineer told The Tampa Tribune that the situation was "unprecedented." He said the edges are steep and unstable, so the hole is likely to grow.

Janell Wheeler told the Tampa Bay Times she was inside the house with four other adults, a child and two dogs when the sinkhole opened.

"It sounded like a car hit my house," she said.

It was dark. She remembered screams and one of her nephews rushing to rescue his brother, trapped in the debris.

Wheeler's house was condemned. The rest of the family went to a hotel, but she stayed behind with her dog, sleeping in her car.

"I just want my nephew," she said through tears.

AnthonyRandazzo, an expert in sinkholes, said he knows of only two people --both in Florida -- who have died because of a sinkhole in 40 years ofstudying the geological phenomenon.

"Usually, you have some time,"said Randazzo, who has lectured on sinkholes at Oxford University."These catastrophic sinkholes give you some warning over the course ofhours. This is very unusual and very tragic."